Art of treating pasteboard



Jan. 12%,1927. 1,614,869

J. M. BROWN ART OF TREATING PAS TEBOARD Filed August 13, 1923 INVENTOR.

A TTORNE Y.

Patented Jan. 18 1927.-

JAM ES MORRIS ZBIROWN OF PHILADELPHIA, PENNSYLV ART or ram'rmqres'rrnomn.

Application filed August 13, 1923. Serial No. 657,255.

For certain purposes and uses it is desirable that pasteboard sheets or sheets made from what is ordinarily and generally known as paperLstock or articles made from such sheets shall be more dense and stronger than such sheets or articles made therefrom usually. are, and also that the same shall be .prl'actically impervious to moisture and to 01' S. It is one of the objects of the'present invention to treat sheets of pasteboard and sheets of similar material in the form of disks or of other shape or form in a manner to render the same firmer, harder and more resistant to liquid, such as water, oil and the like, than heretofore has been the case insofar as I am aware.

A further object of the invention is to subv ject sheets of the said material in disk or 0 other form to the action of a heated material which when in such condition is adapted to enter the pores of the said sheets, fill the same and render the said sheets impervious to liquids, such as water and oils. A still further object of the invention is to provide a method or art by the employment of which sheets of pasteboard or the like may be impregnated with sulphur, montan wax or the like whereby' the said '30 sheets are rendered practically impervious to liquids, such as water andoils.

My invention is not limited toapparatus of any particular character or form, but it will be understood that some form of apparatus is necessary to the carrying out of the same; hence, to facilitate a description of the invention I have illustrated one simple and convenient form of apparatus which may be employed. In the drawing:

Fig. 1 is a view in vertical longitudinal section, taken on the line 11 of Fig. 2,

of an apparatus which may be employed in the carrying out of the invention; and

Fig. 2 is a transverse sectional view of the same taken on the line 22 of Fig. 1.

Referring to the drawingi 1 -designates the lower or body portion of a tank supported u'ponlegs 2. The lower portion 1 of the tank is adapted to be filled with the medium with which the pasteboard sheets or objects made of such sheets are to be impregnated. In the carrying out of my process I have heretofore employed either molten montan wax or sulphur.

Either of these materials is placed within the portion 1 of. the tank and melted and maintained at a temperature of about two hundred and fifty degrees Fahrenheit by means of superheated steam inpipes 4 and 5, the former being located upon the sides and ends of the portion 1 of the tank and the latter upon the bottom'thereof. The top level of the molten material is indicated at 6.

The bottom portion -1 of the tank is closed by a supplemental top portion 10, the bottom edges of which rest upon the flanges 11 at the upper edges of the sides and ends of the portion 1 of the tank. The oppositeends of the cover 10 are provided with hinged doors 11 and 12 for closing openings therein, as shown.

Sprocket wheels 13 are arranged in pairs in the opposite end portions of the interior of the tank. These sprocket wheels are secured upon shafts 14 which are mounted in bearings 15 upon the side flanges of the body portion 1 of the tank, as is quite clearly indicated or shown in Fig. 2 of the drawings. a

Mounted upon these sprocket wheels are endless chain conveyors 16 and 17, each of which is provided with lugs 18 at intervals provided with openings 19 therein through which the opposite ends of rods 20 are adapted to project. These rods are situated at intervals, as shown in Fig. 1, and support disks 25 of pasteboard or sheet material made or constructed of what is ordinarily or generally known as paper stock. The sheets may, however, comprise other material, such as asbestos. The disks of sheet material upon the rods 20 are held in separated relation with respect to each other by means of the corrugated separating or spacing plates 26 of metal or other suitable material.

It is not always essential or necessary but it is preferable that before the sheets or articles, such as spools, made therefrom are subjected to the action of molten sulphur or molten wax all or practically all moisture shall be removed therefrom. The simplest and most convenient way of removing such moisture is by subjecting the sheets to the action of a drying furnace or oven, but the manner in which such moisture is removed is immaterial. w

- For the purpose of subjecting the sheets in the form of disks or of otherv shape to the action of molten wax or sulphur the said disks are threaded upon the rods 20 with the spacing of corrugated plates 26 intermediate lOl - intervals upon the sprocket chains 16 and 17.

It is preferable that a considerablenumber of disks be treated at once and -forthat reason a number of rods are filled with disks which are placed upon the chains by opening one of the doors 11 or 12 after which the conveyor chains are moved so as to carry the said disks into the bottom portion of the tank to submerge the same in the molten impregnating material, such as sulphur or wax. The disks having been allowedto remain submerged in the said molten material for a sufiicient length of time to fully impregnate the same the conveyor chains are then moved so as to carry the said disks into positions in the top portion of the tank above the impregnating material. Before moving the said disks into such position, however, or at least simultaneously with such movement, additional rods with disks thereon are placed uponthe chain, which additional disks are carried downwardly into the treating liquid as the others which have been treated are moved out of the same. While the second batch are being impregnated by the impregnating material "the first batch already impregnated are being subjected to a cooking and drying action inthe upper portion of-the' tank above the top level of the molten impregnating materiaL- Such cooking and drying out removes all externalv material and leaves the disks dry, firm and hard.

The period of time during which the disks must be treated cannot-be stated definitely because it varies not only with the dimensions of the disks both as to thickness of material and diameter, but also is dependent upon the manner in which the sheets have been manufactured. If, in the manufacture thereof, they have been submitted to relatively great pressure soas to compact and condense the same, or if they have been calendered so that the opposite sides thereof are smooth and hard the heated molten impregnating material is absorbed thereby more slowly than would be, the case if re duced pressures had been employed in the manufacture thereof. Except for the difference in material employed the process fol- -lowed is identical whether sulphur or wax be used as the impregnating ingredients. v

The art or met 0d constituting my invention and herein described has been employed heretofore for the treatment ofdisks intended for use as the head or ends of spools although it will be understood that the said disks may be used for any other purpose for whichthey may be adapted.

In the case of disks treated with molten montan wax, particularly where the said disks are to be employed or used in the pres ence of oil, it may be found desirable to subeia-mee jcct the same to a further treatment consisting in subjecting them to the..action of washing soda (sodium carbonate) in solution. The disks after having been impregnated with the molten montan wax and thereafter subjected to a cooking and drying action as above described may thereafter be immersed in a solution of washing soda. ment is found to render'the disks completely impervious to oils. In! some cases this may Such treatthat my invention is not limited to the use of this specific wax and that any other suitable mineral wax may be employed.- By the term montan wax herein used I intend to include not only the specific wax known in the market by that name but also other mineral waxes of like character and qualities.

It will be seen that by my invention 1 have provided an art or method by the employment of which relatively porous disks of pasteboard or the like may be rendered .dense and practically impervious to moisture and to oils.

Having thus described my invention what I claim and desire to secure by Letters Patent is:. '1. The art or method of treating pasteboard sheets which comprises the melting of a wax within a closed receptacle and maintaining the same at a' temperature of about two hundred and fifty degrees Fair renheit, the said wax being solid at normal atmospheric temperature and pressure and of a character such that when pasteboard sheets are impregnated therewith they are rendered practically impervious to oil and water, placing the said sheets within 'the said molten wax and retaining the same therein for a period of time sufficient to effeet impregnation thereof, removing the said sheets from the said molten wax to a position within the said receptacle above the top level of the said wax and maintaining the same in such position until they have completely dried, and thereafter placing the same in. a solution of washing soda.

2. The art or method of treating pastehoardsheets which comprises the melting of a wax within a closed receptacle and maintaining the same at a temperature of about two hundred and fifty degrees Fahrenheit, the said wax being solid at normatatmospheric temperature and pressure andof a 1,014,1aee.

charactei such that when pasfieboarcl sheets are impre nated therewith they are rendered practically impervious to oil and WHXBI,"

placing the said sheets within the said molten Wax and retaining/the some therein for a period of time sufficient to efiect impregnation thereof, remo iing the said sheets from the said molten to a position within the said receptacle above the lop level of the said Wax and maintaining the same in such 10 position until they have completely dried and thereafter immersing the same in a solution of Washing soda,

In testimony that I claim the foregoing as my invention, I have hereunto name this'lst day of August; A. D., 1923.

JAMES MORRIS BROWN.

signed my 15 

